Rocks and clocks help unravel the mysteries of ancient Earth

August 25, 2011

(PhysOrg.com) -- Research into the dating techniques used to identify the origins of the living world has found the way in which fossils are used to calibrate the Earths evolutionary clock is of critical importance. The findings could help us better understand the gaps in the evolutionary timeline.

The study, led by academics at the University of Bristol and published in Biology Letters, analysed how the molecular clock and fossil record align to determine how the Earths environment and living world have co-evolved.

The genes of living animals serve as timekeepers of the planets history and can be used to determine events that happened millions of years ago, from the origin of ancient life forms to the diverge between humans and chimps.

To estimate the pace at which the hands of the molecular clock tick, it is necessary to 'calibrate' the clock by referencing the fossil record.

Historically, there have been controversial differences between the times predicted by the molecular clock and the fossil record. This is because the hands of the clock start ticking before novel life forms make their way into the rock record. Furthermore, not everything is recorded - the rarity of animals and plants found in the fossil record further serves to create major gaps in the timeline.

The researchers found the way in which fossils are used to calibrate the molecular clock is of critical importance  a fact that has been frequently disregarded in most molecular clock studies attempting to provide a timeline for lifes history.

It has become commonplace for molecular biologists to second-guess how fossils can be used to calibrate the molecular clock. However, the findings confirm that this strategy can generate misleading scenarios about the origins of the living world.

Rachel Warnock, the lead researcher from the Universitys School of Earth Sciences, said: Without being able to place events of the past on a timeline, it becomes difficult to understand how the planets environment and the living world have co-evolved. Ultimately, the past provides a key to understanding the present and the future of the planet.

The team of researchers from the University of Bristol and University College London adopted a cross-disciplinary approach combining the expertise of both molecular biologists and palaeontologists.

As we are approach five decades since the discovery of the molecular clock the team predict a more promising future for unravelling the past.

Rachel added: If we want to piece together the crucial environmental events that have shaped the planet, it is vital that biologists and palaeontologists continue working together.

Our next aim is to stimulate further collaboration between palaeontologists and biologists and continue building our vision of Earths mysterious past.

The paper, entitled Exploring uncertainty in the calibration of the molecular clock by Rachel C. M. Warnock and Philip C. J. Donoghue from the University of Bristol and Ziheng Yang from University College London, is published today [24 Aug] in Biology Letters.

Related Stories

It doesn't tick, it doesn't have hands, and it doesn't tell you what time of day it is. But a molecular clock does tell time -- on an epoch scale. The molecular clock, explained S. Blair Hedges, is a tool used to calculate ...

(PhysOrg.com) -- In Civilization and Its Discontents, Sigmund Freud argued that modern society was hard on human psychology, forcing people to get along in unnaturally close quarters. Now newly published research from The ...

(PhysOrg.com) -- A remarkably well-preserved fossil discovered in northeast China provides new information about the earliest ancestors of most of today's mammal speciesthe placental mammals. According to a paper published ...

(PhysOrg.com) -- University of Manchester scientists have helped identify the key trigger mechanism in the internal clocks of animals which means they are prepared for the season whether snow comes in November ...

Since 2008, MIT economist Tavneet Suri has studied the financial and social impacts of Kenyan mobile-money services, which allow users to store and exchange monetary values via mobile phone. Her work has shown that these ...

Researchers have discovered a dinosaur tail complete with its feathers trapped in a piece of amber. The finding reported in Current Biology on December 8 helps to fill in details of the dinosaurs' feather structure and evolution, ...

Reporting new research results involves detailed descriptions of methods and materials used in an experiment. But when a study uses computers to analyze data, create models or simulate things that can't be tested in a lab, ...

Nothing ruins a potentially fun event like putting it on your calendar. In a series of studies, researchers found that scheduling a leisure activity like seeing a movie or taking a coffee break led people to anticipate less ...

(Phys.org)—Douglas Petrovich, an archaeologist with Ontario's Wilfrid-Laurier University in Canada has sparked controversy in the ancient history scholarly community by making claims that he has found proof that Hebrew ...

3 comments

The dating game is such fun--using the unknown that is being measured (fossil age) to calibrate the gauge that is used to measure it (radiometric age). It would be nice to have a less circular approach to verifying age data.

There are so many unjustified assumptions that have to be made to date ANYTHING related to the past that one can usually laugh off the resultant ages that get derived from the physical artifacts.

Here they are assuming that the genetic "molecular clock" is in itself a valid way to measure time. How on earth are they going to calibrate it in a meaningful way since the fossils that lived in the distant past are not going to deliver their DNA for analysis. And if it did, then one would have to query whether those items could be millions of years old in the first place [because DNA just doesn't last that long, except in the evolutionary mythical world].Evolution is the religion[mega-faith required] of the well-informed, highly educated since those who believe in a young [approx. 6000 years ] old earth are idiots and uneducated fools.